During a cardiac procedure, the condition of the heart may be monitored, inter alia, by observing electrophysiological data in a graphical form, typically as potential vs. time graphs. While the heart is in a sinus condition, the periodic electrocardiogram (ECG) waveforms generated by the heart are relatively uncomplicated. However, in some non-sinus conditions of the heart, such as during atrial fibrillation, each periodic ECG signal may include one or more features that may only occur in some of the periodic signals, but not in every signal. Because of the irregularity of the signals, it is difficult to distinguish these features.
PCT Application WO 2010/054409, to Ramanathan et al., whose disclosure is incorporated herein by reference, describes a method for visualization of electrophysiology data. Electroanatomic data representing electrical activity on a surface of an organ over a time period is stored. An interval within the time period is selected in response to a user selection. Responsive to the user selection of the interval, a visual representation of physiological information for the user selected interval is generated by applying at least one method to the electroanatomic data. The visual representation is spatially represented on a graphical representation of a predetermined region of the surface of the organ.
U.S. Patent Application 2013/0245476, to Takizawa et al., whose disclosure is incorporated herein by reference, describes a cardiac muscle excitation waveform detector. The detector includes a waveform acquisition section that acquires, in a preset period, a waveform from an intracardiac electrocardiogram measured in the middle of occurrence of atrial fibrillation. The disclosure is stated to show a result of a mean conduction time that is calculated under an analysis technique described in the disclosure.
U.S. Patent Application 2007/0208260, to Afonso, whose disclosure is incorporated herein by reference, describes a system for presenting information representative of patient electrophysiological activity, such as complex fractionated electrogram information. The disclosure describes a presentation device that presents electrogram information as associated with a location at which it was measured on a model of the patient's heart.
Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that, to the extent that any terms are defined in these incorporated documents in a manner that conflicts with definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.